Alex Brandon, The Associated PressSen. David Vitter believes low interest rates are contributing to high gasoline prices across the country.

Earlier, Vitter went on CNBC to say he believes there is a connection and that he intended to ask the Fed chairman whether the low interest policies should be re-examined.

Bernanke responded to Vitter's questions by saying low interest rates can play a role in higher commodity prices. But he said a far greater factor causing higher gas prices are fears of a disruption in imported oil because of a possible conflict with Iran over what the United States and other nations say are its attempt to gain nuclear weapons,'

Bernanke also cited continued unrest in the Middle East and Africa that threaten oil imports to the United States as major contributors to the large increase in gas prices.

Bernanke told Vitter that low interest rates are having a beneficial effect on the still struggling U.S. economy by making low-cost capital available to consumers and businesses, and that those benefits outweigh any negative impacts.

Vitter was reflecting the view of some economists who believe the Federal Reserve's near zero interest rate policies tends to weaken the U.S. dollar while causing investors to invest in commodities -- both of which contribute to higher prices, particularly for gasoline.

Bernanke said the Federal Reserve is concerned about the impact of low interest rates on commodity prices, though he says the impact is relatively small. He also said the Federal Reserve is sensitive to the problems they cause Americans who keep their money in savings accounts and certificates of deposits, which often pay out interest rates below one percent. He said the Federal Reserve's analysis indicates the benefits of low interest rates, including "increased consumption and investment spending and so on," produces far more benefits for the U.S. economy than some of the negatives cited by Vitter and other critics.